Sprayers or sprayer attachments are widely used on the faucets of kitchen sinks, washroom lavoratories, laundry room sinks and for a wide variety of other applications. Generally faucet sprayers are threaded or otherwise attached to the spout of a faucet to allow a user to adjust the faucet discharge from a stream, which may include an aerated stream, to a spray, or a combination of a stream and a spray.
The first significant introduction of faucet sprayers into the marketplace occurred in or around the late 1940's. At that time various manufacturers offered a flexible rubber sprayer that could be press-fit onto the end of an unthreaded faucet spout. Somewhat later the same sprayer was supplied with a threaded coupling that allowed it to be threaded onto the end of faucets having either internal or external threads.
This early form of faucet sprayer was generally a low-pressure sprayer, as the flow of water was not impeded in any significant manner. The holes to the sprayer were sufficiently large and numerous to prevent the build-up of pressure within the sprayer body, hence preventing the sprayer body from expanding like a balloon or causing the internal pressure to blow the sprayer off the end of the faucet. The diameter of the holes and their number generally resulted in water exiting the sprayer in a series of small low pressure streams.
In or around the 1960's higher pressure faucet sprayers were developed which were different from the previous low pressure sprayers in two significant ways. First, the high pressure sprayers were sealed units that allowed a build-up of water pressure within them so that high pressure could be forced through smaller spray holes, thus producing a strong rinsing-type spray. In many cases an aerator was added that, together with the high build up of pressure water within the sprayer body, was capable of providing a strong aerated stream when desired.
The second primary advancement that came about when high pressure sprayers were designed was the incorporation of a swivel or ball and socket type joint that allowed the direction of the spray to be altered. In addition, the sprayers were formed from hard plastic or metallic bodies that were designed to withstand the increased pressure and that also facilitated the use of a vertical valve arrangement within the sprayer to permit a consumer to switch from a spray to an aerated flow pattern. Such high pressure sprayers remain in wide use today and are manufactured in numerous sizes and physical configurations.
Although high pressure faucet sprayers provide a number of advantages over previous low pressure devices, currently available faucet sprayers still suffer from a number of inherent limitations. First, the vertical valving structure that is utilized on most sprayers requires a user to grasp and physically pull down or push up upon the spray head in a vertical plane in order to change from a spray to an aerated flow pattern. Such movements can put a considerable amount of torque or stress upon the faucet, as well as the faucet/sprayer connection. Where the hardness of the water is relatively high, mineral deposits within the sprayer body can make it difficult to switch between a spray and an aerated flow pattern, thereby requiring the application of additional force and putting yet further strain upon the faucet and the sprayer/faucet connection. Mineral deposits also tend to accumulate on ball and socket or swivel joints making them difficult to operate.
Currently available faucet sprayers also provide only a limited ability for moving the spray head relative to the faucet and angling the discharge away from a vertical plane. To increase the range of movement others have suggested the use of a double ball and socket type structure. To some degree a double ball and socket structure increases the ability to direct the spray further from a vertical plane, however, only at the expense of a more complicated mechanical structure, increased cost, and even greater susceptibility to the negative effects of hard water.